1. Field of the Invention
The present invention is generally related to a novel crystalline polymorph, and more particularly to crystalline polymorphs of acetyl-glycine-beta-alanine and process of making the same.
2. Description of the Prior Art
The application and synthesis of acetyl-glycine-beta-alanine as the following structure (1) was disclosed in WO 2012/051741A1 and U.S. patent application Ser. No. 13/128,446.

Acetyl-glycine-beta-alanine was taught to be capable of inhibiting melanin formation and exhibited good color stability in the cosmetic formulation in U.S. patent application Ser. No. 13/128,446.
Recently, more study about the mechanism of inhibiting melanin formation was completed and the results showed acetyl-glycine-beta-alanine down-regulated a key regulator of melanin synthesis (MITF) expression −37% and also reduced tyrosinase, TRP-1, and TRP-2 protein level at −41%, −41%, and −75% respectively. Ex vivo test in a tissue model of the human epidermis prepared from cultured human keratinocytes and melanocytes showed 2% of acetyl-glycine-beta-alanine exhibited excellent whitening efficacy (existing melanin level: −30%) in 9 day. In vivo human study also showed spot-brightening (51.67% age spot reduction) after 14 days. In another in vitro study for evaluating anti-inflammation effect, acetyl-glycine-beta-alanine also showed reduced IL-6 and IL8 level after exposure of human epidermal keratinocytes on UVB light.
A method of synthesis of acetyl-glycine-beta-alanine was described in U.S. patent application Ser. No. 13/128,446. The crude acetyl-glycine-beta-alanine which was obtained by concentration after hydrogenation was a mixed crystalline polymorph and its HPLC purity was only more than 95%. However, for active ingredients used in cosmetic and pharmaceutical industries, it is always required that higher HPLC purity more than 99%, stable crystalline polymorph and excellent storage stability. As a result, there is a need for developing a stable crystalline polymorph of acetyl-glycine-beta-alanine, which is more suitable for its application.